Backstage at Reading University on the first night of the band's UK tour, My Bloody Valentine main man Kevin Shields cowers in bashful bemusement under a barrage of hysterical praise from 20-year-old superfan Jason Kelpie.

"If the world ended tomorrow and there was nothing left but My Bloody Valentine, I'd be happy. They are the coolest f---ing sonic visual experience we've got. You can't beat My Bloody Valentine with a big stick! Only having your brains blown out with a massive shotgun while on acid comes close to My Bloody Valentine! Worship at the altar of My Bloody Valentine! Religion sucks, but the closest thing to religion we've got is My Bloody Valentine..."

Strange that four outwardly calm individuals should consistently attract such extreme reactions. A band whose languorous work-rate makes three-toed sloths seem hyperactive, who never commit themselves to even the vaguest statement of intent, who dress like woolly mammoths and spurn the glittering limelight of cult success. A band whose lyrics rarely refer to anything remotely recognizable and whose alien music screams down from a candy-floss Valhalla, rubbing its sleepy eyes as it plummets earthwards.

Yes indeed, there's plenty more where that came from — MBV have inspired more fanciful flights of purple journalistic prose than any other group of the past decade, for one simple reason: the sheer face of swirling noise that is the Valentines in full flight presents a blank canvas eight miles high for whatever open-ended interpretation the beholder wants to project there. Drugs is an obvious favorite. Sex and dreams and extreme violence are up there, too. Very few critics mention aquariums or kitchen utensils, but they might just as well do.

Such vanities are not on Kevin's mind after the Reading show. Characteristically modest in his critical post-mortem, he complains: "It was really mediocre, the sound was awful onstage, we played badly."

Not strictly true. There are slack moments of routine grunge-rock in tonight's set, but everything else is a fiercely controlled fireworks display of overheating psychedelic noise. Strafed by strobes and bathed in eerie purple light, the Valentines surgically extract immaculate sound-symphonies from their awesome new album Loveless, and methodically mutilate them almost beyond recognition. Bone-crunching dance beats and ethnic twiddles from their two recent EPs, 'Glider' and 'Tremolo', also make a strong showing. But it is the fragments of 1988's seminal Isn't Anything LP that really rock Reading, particularly a mutant cousin of 'Feed Me With Your Kiss' which emerges from an ear-splitting ten-minute encore of apocalyptic thunder. World War III contained on a single stage — call MBV an art band if you want, but this brain-bending display is the closest thing to the catharsis called rock 'n' roll anyone here has ever witnessed.

It amounts to a triumphant piece of self-justifying theater from a band many thought could never match the slamming brilliance of Isn't Anything, a band shrouded for three years in rumors concerning scrapped recordings and suicidally spiraling studio costs. Fixing a price tag upwards of £250,000 on the long-overdue Loveless, the music press predicted bankruptcy for MBV's label, Creation, and hot water for Kevin if he didn't deliver something with platinum potential. Judging by the album's critical reception, the future of both band and label seems assured.

When the buzzing hordes of acolytes from post-Valentines bands Ride, Lush, Chapterhouse and Slowdive dissipate from the dressing room in Reading, Kevin is finally willing to nail those rumors.

"Creation are no closer than any other label to going bankrupt," he offers ambivalently, confirming the astronomical figure quoted above but stressing this also covered two expensive EPs, three videos and the band's living costs over three years. "They paid for everything bit by bit so they'd eaten up the cost as they went along. They felt strained, but nothing special: they would spend easily as much on two or three smaller bands."

Creation themselves are understandably cagey about discussing their financial dealings with MBV, or how the strain has affected their relationship with the group. However, one source contradicts Kevin by hinting that the quarter-million figure belongs to Loveless only. Enigmatic label boss Alan McGee will only reveal "It cost a lot of money, but we all love the album".

In their pre-Creation days, MBV discovered a sonic frequency which causes physical pain and purposely used it to make their live sets very uncomfortable for audiences: "We did it for a few years when we thought we were massively misunderstood, when we were just perceived as a twee pop band." So with tonight's sturm und drang finale, is Kevin still trying to hurt people with sound? "No, it's just pure noise for the hell of it. The fun is in watching people's faces. That's why we light the audience up, to see their discomfort."

Belying his hulking frame, Kevin whispers with a sing-song Irish burr, the legacy of a childhood spent mostly in Dublin, where he and Valentines' drummer Colm O'Coisoig had their first forays into the sonic twilight zone dismissed by an insular pop community.

"I did all my progressive stuff years before I came to this country. I loved bands like the Ramones and didn't know much about the history of music, so as far as I was concerned the Ramones appeared from nowhere. I didn't know about all these '60s garage punk bands. I was hung up for a few years on the idea that you had to be original; me and Colm spent two years making original music but it was boring and uninspired. We weren't doing it for the right reasons."

Decamping to Europe on the advice of former Virgin Prune Gavin Friday, the nascent Valentines — now incorporating guitarist Bilinda Butcher, bassist Debbie Googe and a short-lived singer called Dave — enjoyed eight months of debauchery in Berlin and Amsterdam before arriving in London just in time to collide with the C86 indie movement. An unwanted reputation for jangly feyness was foisted upon them, largely due to their weedy first efforts on Lazy, the label run by Primitives manager Wayne Morris. A stormy marriage, as Kevin recalls.

"That was a disaster — it taught us about not trusting people. Wayne Morris was just so evil to us, him and The Primitives, we fell out with him before we even finished the record. He was so ruthless, he had no respect for the idea of people making music. The Primitives were more manufactured than any Stock Aitken Waterman band. I've seen Wayne tell the guitarist to completely change his hairstyle, he told Tracey he would have her making love to the microphone in a miniskirt within six months...and he did!"

Leaving Lazy — and Dave — behind, MBV reinvented themselves for Creation as merchants of dreamy pop tunes clothed in juddering noise volcanoes. With Kevin as main songwriter, the channeled feedback eruptions and bent-out-of-shape guitars on Isn't Anything hung in the air like jet-propelled abstract art, a rootless and seemingly unassailable precipice of pure pop. Suddenly, name-checking the Valentines became hip and indie hopefuls began roughing up their sound all over Southern England.

Remembering the fickleness of public opinion, Kevin questions the true extent of his band's influence.

"The only thing we've definitely done on our own is having something aggressive and caustic but at the same time really liquid and fluid. It's always impossible to see yourself in other people. Most of the bands that are seen to be influenced by us, their strange sounds come from using lots of effects. There's no effect in existence you could plug into and have our sound, it's just the way we treat things, mainly the tremolo arm on our guitars...the way I think about sound is like a picture in my head, a textured picture. I'm thinking of writing them down some day."

That should make interesting reading for Oxford's Ride, who caught most of the flak for being prime MBV copyists, partly due to sharing the same label. Singer Mark Gardiner acknowledges the inspiration but denies jumping on the bandwagon: "If we'd wanted to be part of any scene when we started we'd have put on baggy trousers and pretended to come from up North. We're on Creation for the same reason a lot of bands are, because it's a label that lets you do what you want, they give you freedom. To me all these bands don't sound alike at all."

One significant difference between the Valentines and their descendants is their distance from the social scene which loosely binds these younger bands. Despite a professed love of Ecstasy, House and especially hip hop — "it beats the shit out of most rock music when it comes to being experimental, it's been a constant source of inspiration to us" — Kevin generally avoids clubs and pop-star ligging. His long-term involvement with Bilinda and her eight-year-old son Toby keeps him away from frantic socializing, but does this relationship fuel MBV's music?

Sleepy-eyed Bilinda is doubtful. "It's funny because people have said there is a feminine sound to the music, but the music comes from Kevin. Obviously if I'm singing it's going to have a feminine touch to it, but quite often people mistake mine and Kevin's voices anyway...it's probably more androgynous than actually feminine."

Kevin confesses this is a deliberate strategy. "Our lives have been too real to talk about. Not glamorous stuff like getting arrested for drugs or whatever, it's more mundane domestic shit that really f--ks you up, personal things that are totally beyond the experience of the average student. Bilinda happened to bring up a kid under bad circumstances, it's very real, we don't really talk about it. That's why we often think we might break up because the band seems too trivial sometimes..."

After dropping a few more hints — family trauma, depression, immigration hassles — Kevin steers our conversation into calmer waters. The band's recent live debuts in Japan and Australia energized him, but touring Britain remains a daunting prospect.

"When we tour we tend to get wrecked a lot from sheer boredom: you're allowed to be a complete idiot and it's not seen as something stupid," he chuckles.

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